Heat the butter in a large frying pan. Add the onion, sweet and chili peppers, and fry until the onion is soft but not brown. Add the tomatoes, salt and pepper to taste, sugar, bay leaf, and parsley. Simmer uncovered for 30 minutes. Remove and discard the bay leaf and parsley sprigs. Add the shrimp and cook for 3 to 5 minutes, or until they have lost their translucent look. Stir in the lime or lemon juice.{$7e}(Original recipe for 4)
